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authorArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2008-07-14 19:08:37 +0300
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2008-07-15 17:35:15 +0300
commit1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d (patch)
tree919debdd48aef9eee9ff0e8f465ef2649325b993 /fs/ubifs/log.c
parente56a99d5a42dcb91e622ae7a0289d8fb2ddabffb (diff)
UBIFS: add new flash file system
This is a new flash file system. See http://www.linux-mtd.infradead.org/doc/ubifs.html Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Diffstat (limited to 'fs/ubifs/log.c')
-rw-r--r--fs/ubifs/log.c805
1 files changed, 805 insertions, 0 deletions
diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
new file mode 100644
index 00000000000..36857b9ed59
--- /dev/null
+++ b/fs/ubifs/log.c
@@ -0,0 +1,805 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ * Adrian Hunter
+ */
+
+/*
+ * This file is a part of UBIFS journal implementation and contains various
+ * functions which manipulate the log. The log is a fixed area on the flash
+ * which does not contain any data but refers to buds. The log is a part of the
+ * journal.
+ */
+
+#include "ubifs.h"
+
+#ifdef CONFIG_UBIFS_FS_DEBUG
+static int dbg_check_bud_bytes(struct ubifs_info *c);
+#else
+#define dbg_check_bud_bytes(c) 0
+#endif
+
+/**
+ * ubifs_search_bud - search bud LEB.
+ * @c: UBIFS file-system description object
+ * @lnum: logical eraseblock number to search
+ *
+ * This function searches bud LEB @lnum. Returns bud description object in case
+ * of success and %NULL if there is no bud with this LEB number.
+ */
+struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum)
+{
+ struct rb_node *p;
+ struct ubifs_bud *bud;
+
+ spin_lock(&c->buds_lock);
+ p = c->buds.rb_node;
+ while (p) {
+ bud = rb_entry(p, struct ubifs_bud, rb);
+ if (lnum < bud->lnum)
+ p = p->rb_left;
+ else if (lnum > bud->lnum)
+ p = p->rb_right;
+ else {
+ spin_unlock(&c->buds_lock);
+ return bud;
+ }
+ }
+ spin_unlock(&c->buds_lock);
+ return NULL;
+}
+
+/**
+ * ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one.
+ * @c: UBIFS file-system description object
+ * @lnum: logical eraseblock number to search
+ *
+ * This functions returns the wbuf for @lnum or %NULL if there is not one.
+ */
+struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum)
+{
+ struct rb_node *p;
+ struct ubifs_bud *bud;
+ int jhead;
+
+ if (!c->jheads)
+ return NULL;
+
+ spin_lock(&c->buds_lock);
+ p = c->buds.rb_node;
+ while (p) {
+ bud = rb_entry(p, struct ubifs_bud, rb);
+ if (lnum < bud->lnum)
+ p = p->rb_left;
+ else if (lnum > bud->lnum)
+ p = p->rb_right;
+ else {
+ jhead = bud->jhead;
+ spin_unlock(&c->buds_lock);
+ return &c->jheads[jhead].wbuf;
+ }
+ }
+ spin_unlock(&c->buds_lock);
+ return NULL;
+}
+
+/**
+ * next_log_lnum - switch to the next log LEB.
+ * @c: UBIFS file-system description object
+ * @lnum: current log LEB
+ */
+static inline int next_log_lnum(const struct ubifs_info *c, int lnum)
+{
+ lnum += 1;
+ if (lnum > c->log_last)
+ lnum = UBIFS_LOG_LNUM;
+
+ return lnum;
+}
+
+/**
+ * empty_log_bytes - calculate amount of empty space in the log.
+ * @c: UBIFS file-system description object
+ */
+static inline long long empty_log_bytes(const struct ubifs_info *c)
+{
+ long long h, t;
+
+ h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
+ t = (long long)c->ltail_lnum * c->leb_size;
+
+ if (h >= t)
+ return c->log_bytes - h + t;
+ else
+ return t - h;
+}
+
+/**
+ * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
+ * @c: UBIFS file-system description object
+ * @bud: the bud to add
+ */
+void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
+{
+ struct rb_node **p, *parent = NULL;
+ struct ubifs_bud *b;
+ struct ubifs_jhead *jhead;
+
+ spin_lock(&c->buds_lock);
+ p = &c->buds.rb_node;
+ while (*p) {
+ parent = *p;
+ b = rb_entry(parent, struct ubifs_bud, rb);
+ ubifs_assert(bud->lnum != b->lnum);
+ if (bud->lnum < b->lnum)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+
+ rb_link_node(&bud->rb, parent, p);
+ rb_insert_color(&bud->rb, &c->buds);
+ if (c->jheads) {
+ jhead = &c->jheads[bud->jhead];
+ list_add_tail(&bud->list, &jhead->buds_list);
+ } else
+ ubifs_assert(c->replaying && (c->vfs_sb->s_flags & MS_RDONLY));
+
+ /*
+ * Note, although this is a new bud, we anyway account this space now,
+ * before any data has been written to it, because this is about to
+ * guarantee fixed mount time, and this bud will anyway be read and
+ * scanned.
+ */
+ c->bud_bytes += c->leb_size - bud->start;
+
+ dbg_log("LEB %d:%d, jhead %d, bud_bytes %lld", bud->lnum,
+ bud->start, bud->jhead, c->bud_bytes);
+ spin_unlock(&c->buds_lock);
+}
+
+/**
+ * ubifs_create_buds_lists - create journal head buds lists for remount rw.
+ * @c: UBIFS file-system description object
+ */
+void ubifs_create_buds_lists(struct ubifs_info *c)
+{
+ struct rb_node *p;
+
+ spin_lock(&c->buds_lock);
+ p = rb_first(&c->buds);
+ while (p) {
+ struct ubifs_bud *bud = rb_entry(p, struct ubifs_bud, rb);
+ struct ubifs_jhead *jhead = &c->jheads[bud->jhead];
+
+ list_add_tail(&bud->list, &jhead->buds_list);
+ p = rb_next(p);
+ }
+ spin_unlock(&c->buds_lock);
+}
+
+/**
+ * ubifs_add_bud_to_log - add a new bud to the log.
+ * @c: UBIFS file-system description object
+ * @jhead: journal head the bud belongs to
+ * @lnum: LEB number of the bud
+ * @offs: starting offset of the bud
+ *
+ * This function writes reference node for the new bud LEB @lnum it to the log,
+ * and adds it to the buds tress. It also makes sure that log size does not
+ * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
+ * %-EAGAIN if commit is required, and a negative error codes in case of
+ * failure.
+ */
+int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
+{
+ int err;
+ struct ubifs_bud *bud;
+ struct ubifs_ref_node *ref;
+
+ bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS);
+ if (!bud)
+ return -ENOMEM;
+ ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
+ if (!ref) {
+ kfree(bud);
+ return -ENOMEM;
+ }
+
+ mutex_lock(&c->log_mutex);
+
+ if (c->ro_media) {
+ err = -EROFS;
+ goto out_unlock;
+ }
+
+ /* Make sure we have enough space in the log */
+ if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
+ dbg_log("not enough log space - %lld, required %d",
+ empty_log_bytes(c), c->min_log_bytes);
+ ubifs_commit_required(c);
+ err = -EAGAIN;
+ goto out_unlock;
+ }
+
+ /*
+ * Make sure the the amount of space in buds will not exceed
+ * 'c->max_bud_bytes' limit, because we want to guarantee mount time
+ * limits.
+ *
+ * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
+ * because we are holding @c->log_mutex. All @c->bud_bytes take place
+ * when both @c->log_mutex and @c->bud_bytes are locked.
+ */
+ if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
+ dbg_log("bud bytes %lld (%lld max), require commit",
+ c->bud_bytes, c->max_bud_bytes);
+ ubifs_commit_required(c);
+ err = -EAGAIN;
+ goto out_unlock;
+ }
+
+ /*
+ * If the journal is full enough - start background commit. Note, it is
+ * OK to read 'c->cmt_state' without spinlock because integer reads
+ * are atomic in the kernel.
+ */
+ if (c->bud_bytes >= c->bg_bud_bytes &&
+ c->cmt_state == COMMIT_RESTING) {
+ dbg_log("bud bytes %lld (%lld max), initiate BG commit",
+ c->bud_bytes, c->max_bud_bytes);
+ ubifs_request_bg_commit(c);
+ }
+
+ bud->lnum = lnum;
+ bud->start = offs;
+ bud->jhead = jhead;
+
+ ref->ch.node_type = UBIFS_REF_NODE;
+ ref->lnum = cpu_to_le32(bud->lnum);
+ ref->offs = cpu_to_le32(bud->start);
+ ref->jhead = cpu_to_le32(jhead);
+
+ if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
+ c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
+ c->lhead_offs = 0;
+ }
+
+ if (c->lhead_offs == 0) {
+ /* Must ensure next log LEB has been unmapped */
+ err = ubifs_leb_unmap(c, c->lhead_lnum);
+ if (err)
+ goto out_unlock;
+ }
+
+ if (bud->start == 0) {
+ /*
+ * Before writing the LEB reference which refers an empty LEB
+ * to the log, we have to make sure it is mapped, because
+ * otherwise we'd risk to refer an LEB with garbage in case of
+ * an unclean reboot, because the target LEB might have been
+ * unmapped, but not yet physically erased.
+ */
+ err = ubi_leb_map(c->ubi, bud->lnum, UBI_SHORTTERM);
+ if (err)
+ goto out_unlock;
+ }
+
+ dbg_log("write ref LEB %d:%d",
+ c->lhead_lnum, c->lhead_offs);
+ err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
+ c->lhead_offs, UBI_SHORTTERM);
+ if (err)
+ goto out_unlock;
+
+ c->lhead_offs += c->ref_node_alsz;
+
+ ubifs_add_bud(c, bud);
+
+ mutex_unlock(&c->log_mutex);
+ kfree(ref);
+ return 0;
+
+out_unlock:
+ mutex_unlock(&c->log_mutex);
+ kfree(ref);
+ kfree(bud);
+ return err;
+}
+
+/**
+ * remove_buds - remove used buds.
+ * @c: UBIFS file-system description object
+ *
+ * This function removes use buds from the buds tree. It does not remove the
+ * buds which are pointed to by journal heads.
+ */
+static void remove_buds(struct ubifs_info *c)
+{
+ struct rb_node *p;
+
+ ubifs_assert(list_empty(&c->old_buds));
+ c->cmt_bud_bytes = 0;
+ spin_lock(&c->buds_lock);
+ p = rb_first(&c->buds);
+ while (p) {
+ struct rb_node *p1 = p;
+ struct ubifs_bud *bud;
+ struct ubifs_wbuf *wbuf;
+
+ p = rb_next(p);
+ bud = rb_entry(p1, struct ubifs_bud, rb);
+ wbuf = &c->jheads[bud->jhead].wbuf;
+
+ if (wbuf->lnum == bud->lnum) {
+ /*
+ * Do not remove buds which are pointed to by journal
+ * heads (non-closed buds).
+ */
+ c->cmt_bud_bytes += wbuf->offs - bud->start;
+ dbg_log("preserve %d:%d, jhead %d, bud bytes %d, "
+ "cmt_bud_bytes %lld", bud->lnum, bud->start,
+ bud->jhead, wbuf->offs - bud->start,
+ c->cmt_bud_bytes);
+ bud->start = wbuf->offs;
+ } else {
+ c->cmt_bud_bytes += c->leb_size - bud->start;
+ dbg_log("remove %d:%d, jhead %d, bud bytes %d, "
+ "cmt_bud_bytes %lld", bud->lnum, bud->start,
+ bud->jhead, c->leb_size - bud->start,
+ c->cmt_bud_bytes);
+ rb_erase(p1, &c->buds);
+ list_del(&bud->list);
+ /*
+ * If the commit does not finish, the recovery will need
+ * to replay the journal, in which case the old buds
+ * must be unchanged. Do not release them until post
+ * commit i.e. do not allow them to be garbage
+ * collected.
+ */
+ list_add(&bud->list, &c->old_buds);
+ }
+ }
+ spin_unlock(&c->buds_lock);
+}
+
+/**
+ * ubifs_log_start_commit - start commit.
+ * @c: UBIFS file-system description object
+ * @ltail_lnum: return new log tail LEB number
+ *
+ * The commit operation starts with writing "commit start" node to the log and
+ * reference nodes for all journal heads which will define new journal after
+ * the commit has been finished. The commit start and reference nodes are
+ * written in one go to the nearest empty log LEB (hence, when commit is
+ * finished UBIFS may safely unmap all the previous log LEBs). This function
+ * returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
+{
+ void *buf;
+ struct ubifs_cs_node *cs;
+ struct ubifs_ref_node *ref;
+ int err, i, max_len, len;
+
+ err = dbg_check_bud_bytes(c);
+ if (err)
+ return err;
+
+ max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
+ max_len = ALIGN(max_len, c->min_io_size);
+ buf = cs = kmalloc(max_len, GFP_NOFS);
+ if (!buf)
+ return -ENOMEM;
+
+ cs->ch.node_type = UBIFS_CS_NODE;
+ cs->cmt_no = cpu_to_le64(c->cmt_no + 1);
+ ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
+
+ /*
+ * Note, we do not lock 'c->log_mutex' because this is the commit start
+ * phase and we are exclusively using the log. And we do not lock
+ * write-buffer because nobody can write to the file-system at this
+ * phase.
+ */
+
+ len = UBIFS_CS_NODE_SZ;
+ for (i = 0; i < c->jhead_cnt; i++) {
+ int lnum = c->jheads[i].wbuf.lnum;
+ int offs = c->jheads[i].wbuf.offs;
+
+ if (lnum == -1 || offs == c->leb_size)
+ continue;
+
+ dbg_log("add ref to LEB %d:%d for jhead %d", lnum, offs, i);
+ ref = buf + len;
+ ref->ch.node_type = UBIFS_REF_NODE;
+ ref->lnum = cpu_to_le32(lnum);
+ ref->offs = cpu_to_le32(offs);
+ ref->jhead = cpu_to_le32(i);
+
+ ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
+ len += UBIFS_REF_NODE_SZ;
+ }
+
+ ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
+
+ /* Switch to the next log LEB */
+ if (c->lhead_offs) {
+ c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
+ c->lhead_offs = 0;
+ }
+
+ if (c->lhead_offs == 0) {
+ /* Must ensure next LEB has been unmapped */
+ err = ubifs_leb_unmap(c, c->lhead_lnum);
+ if (err)
+ goto out;
+ }
+
+ len = ALIGN(len, c->min_io_size);
+ dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
+ err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len, UBI_SHORTTERM);
+ if (err)
+ goto out;
+
+ *ltail_lnum = c->lhead_lnum;
+
+ c->lhead_offs += len;
+ if (c->lhead_offs == c->leb_size) {
+ c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
+ c->lhead_offs = 0;
+ }
+
+ remove_buds(c);
+
+ /*
+ * We have started the commit and now users may use the rest of the log
+ * for new writes.
+ */
+ c->min_log_bytes = 0;
+
+out:
+ kfree(buf);
+ return err;
+}
+
+/**
+ * ubifs_log_end_commit - end commit.
+ * @c: UBIFS file-system description object
+ * @ltail_lnum: new log tail LEB number
+ *
+ * This function is called on when the commit operation was finished. It
+ * moves log tail to new position and unmaps LEBs which contain obsolete data.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
+{
+ int err;
+
+ /*
+ * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
+ * writes during commit. Its only short "commit" start phase when
+ * writers are blocked.
+ */
+ mutex_lock(&c->log_mutex);
+
+ dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
+ c->ltail_lnum, ltail_lnum);
+
+ c->ltail_lnum = ltail_lnum;
+ /*
+ * The commit is finished and from now on it must be guaranteed that
+ * there is always enough space for the next commit.
+ */
+ c->min_log_bytes = c->leb_size;
+
+ spin_lock(&c->buds_lock);
+ c->bud_bytes -= c->cmt_bud_bytes;
+ spin_unlock(&c->buds_lock);
+
+ err = dbg_check_bud_bytes(c);
+
+ mutex_unlock(&c->log_mutex);
+ return err;
+}
+
+/**
+ * ubifs_log_post_commit - things to do after commit is completed.
+ * @c: UBIFS file-system description object
+ * @old_ltail_lnum: old log tail LEB number
+ *
+ * Release buds only after commit is completed, because they must be unchanged
+ * if recovery is needed.
+ *
+ * Unmap log LEBs only after commit is completed, because they may be needed for
+ * recovery.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
+{
+ int lnum, err = 0;
+
+ while (!list_empty(&c->old_buds)) {
+ struct ubifs_bud *bud;
+
+ bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
+ err = ubifs_return_leb(c, bud->lnum);
+ if (err)
+ return err;
+ list_del(&bud->list);
+ kfree(bud);
+ }
+ mutex_lock(&c->log_mutex);
+ for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
+ lnum = next_log_lnum(c, lnum)) {
+ dbg_log("unmap log LEB %d", lnum);
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ goto out;
+ }
+out:
+ mutex_unlock(&c->log_mutex);
+ return err;
+}
+
+/**
+ * struct done_ref - references that have been done.
+ * @rb: rb-tree node
+ * @lnum: LEB number
+ */
+struct done_ref {
+ struct rb_node rb;
+ int lnum;
+};
+
+/**
+ * done_already - determine if a reference has been done already.
+ * @done_tree: rb-tree to store references that have been done
+ * @lnum: LEB number of reference
+ *
+ * This function returns %1 if the reference has been done, %0 if not, otherwise
+ * a negative error code is returned.
+ */
+static int done_already(struct rb_root *done_tree, int lnum)
+{
+ struct rb_node **p = &done_tree->rb_node, *parent = NULL;
+ struct done_ref *dr;
+
+ while (*p) {
+ parent = *p;
+ dr = rb_entry(parent, struct done_ref, rb);
+ if (lnum < dr->lnum)
+ p = &(*p)->rb_left;
+ else if (lnum > dr->lnum)
+ p = &(*p)->rb_right;
+ else
+ return 1;
+ }
+
+ dr = kzalloc(sizeof(struct done_ref), GFP_NOFS);
+ if (!dr)
+ return -ENOMEM;
+
+ dr->lnum = lnum;
+
+ rb_link_node(&dr->rb, parent, p);
+ rb_insert_color(&dr->rb, done_tree);
+
+ return 0;
+}
+
+/**
+ * destroy_done_tree - destroy the done tree.
+ * @done_tree: done tree to destroy
+ */
+static void destroy_done_tree(struct rb_root *done_tree)
+{
+ struct rb_node *this = done_tree->rb_node;
+ struct done_ref *dr;
+
+ while (this) {
+ if (this->rb_left) {
+ this = this->rb_left;
+ continue;
+ } else if (this->rb_right) {
+ this = this->rb_right;
+ continue;
+ }
+ dr = rb_entry(this, struct done_ref, rb);
+ this = rb_parent(this);
+ if (this) {
+ if (this->rb_left == &dr->rb)
+ this->rb_left = NULL;
+ else
+ this->rb_right = NULL;
+ }
+ kfree(dr);
+ }
+}
+
+/**
+ * add_node - add a node to the consolidated log.
+ * @c: UBIFS file-system description object
+ * @buf: buffer to which to add
+ * @lnum: LEB number to which to write is passed and returned here
+ * @offs: offset to where to write is passed and returned here
+ * @node: node to add
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
+ void *node)
+{
+ struct ubifs_ch *ch = node;
+ int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
+
+ if (len > remains) {
+ int sz = ALIGN(*offs, c->min_io_size), err;
+
+ ubifs_pad(c, buf + *offs, sz - *offs);
+ err = ubifs_leb_change(c, *lnum, buf, sz, UBI_SHORTTERM);
+ if (err)
+ return err;
+ *lnum = next_log_lnum(c, *lnum);
+ *offs = 0;
+ }
+ memcpy(buf + *offs, node, len);
+ *offs += ALIGN(len, 8);
+ return 0;
+}
+
+/**
+ * ubifs_consolidate_log - consolidate the log.
+ * @c: UBIFS file-system description object
+ *
+ * Repeated failed commits could cause the log to be full, but at least 1 LEB is
+ * needed for commit. This function rewrites the reference nodes in the log
+ * omitting duplicates, and failed CS nodes, and leaving no gaps.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_consolidate_log(struct ubifs_info *c)
+{
+ struct ubifs_scan_leb *sleb;
+ struct ubifs_scan_node *snod;
+ struct rb_root done_tree = RB_ROOT;
+ int lnum, err, first = 1, write_lnum, offs = 0;
+ void *buf;
+
+ dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
+ c->lhead_lnum);
+ buf = vmalloc(c->leb_size);
+ if (!buf)
+ return -ENOMEM;
+ lnum = c->ltail_lnum;
+ write_lnum = lnum;
+ while (1) {
+ sleb = ubifs_scan(c, lnum, 0, c->sbuf);
+ if (IS_ERR(sleb)) {
+ err = PTR_ERR(sleb);
+ goto out_free;
+ }
+ list_for_each_entry(snod, &sleb->nodes, list) {
+ switch (snod->type) {
+ case UBIFS_REF_NODE: {
+ struct ubifs_ref_node *ref = snod->node;
+ int ref_lnum = le32_to_cpu(ref->lnum);
+
+ err = done_already(&done_tree, ref_lnum);
+ if (err < 0)
+ goto out_scan;
+ if (err != 1) {
+ err = add_node(c, buf, &write_lnum,
+ &offs, snod->node);
+ if (err)
+ goto out_scan;
+ }
+ break;
+ }
+ case UBIFS_CS_NODE:
+ if (!first)
+ break;
+ err = add_node(c, buf, &write_lnum, &offs,
+ snod->node);
+ if (err)
+ goto out_scan;
+ first = 0;
+ break;
+ }
+ }
+ ubifs_scan_destroy(sleb);
+ if (lnum == c->lhead_lnum)
+ break;
+ lnum = next_log_lnum(c, lnum);
+ }
+ if (offs) {
+ int sz = ALIGN(offs, c->min_io_size);
+
+ ubifs_pad(c, buf + offs, sz - offs);
+ err = ubifs_leb_change(c, write_lnum, buf, sz, UBI_SHORTTERM);
+ if (err)
+ goto out_free;
+ offs = ALIGN(offs, c->min_io_size);
+ }
+ destroy_done_tree(&done_tree);
+ vfree(buf);
+ if (write_lnum == c->lhead_lnum) {
+ ubifs_err("log is too full");
+ return -EINVAL;
+ }
+ /* Unmap remaining LEBs */
+ lnum = write_lnum;
+ do {
+ lnum = next_log_lnum(c, lnum);
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ } while (lnum != c->lhead_lnum);
+ c->lhead_lnum = write_lnum;
+ c->lhead_offs = offs;
+ dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
+ return 0;
+
+out_scan:
+ ubifs_scan_destroy(sleb);
+out_free:
+ destroy_done_tree(&done_tree);
+ vfree(buf);
+ return err;
+}
+
+#ifdef CONFIG_UBIFS_FS_DEBUG
+
+/**
+ * dbg_check_bud_bytes - make sure bud bytes calculation are all right.
+ * @c: UBIFS file-system description object
+ *
+ * This function makes sure the amount of flash space used by closed buds
+ * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
+ * case of failure.
+ */
+static int dbg_check_bud_bytes(struct ubifs_info *c)
+{
+ int i, err = 0;
+ struct ubifs_bud *bud;
+ long long bud_bytes = 0;
+
+ if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
+ return 0;
+
+ spin_lock(&c->buds_lock);
+ for (i = 0; i < c->jhead_cnt; i++)
+ list_for_each_entry(bud, &c->jheads[i].buds_list, list)
+ bud_bytes += c->leb_size - bud->start;
+
+ if (c->bud_bytes != bud_bytes) {
+ ubifs_err("bad bud_bytes %lld, calculated %lld",
+ c->bud_bytes, bud_bytes);
+ err = -EINVAL;
+ }
+ spin_unlock(&c->buds_lock);
+
+ return err;
+}
+
+#endif /* CONFIG_UBIFS_FS_DEBUG */